Magnetic lock for miners&#39; safety lamps



2 SHEETS-SHEET 1 5. WHEAT ET AL MAGNETIC LOCK FOR MINERSK SAFETY LAMPS I I 11/1 I 1/ I .1 1/11 1 /1 1 1 P 2, 1952 G. WHEAT ET AL 2 ,609,487

MAGNETIC LOCK FOR MINERS SAFETY LAMPS Filed May 16, 1951 2 SHEETSSHEET 2 laveni'ofls Gawain; WW, v 016 31210 G.Dav.z3s,

Patented Sept. 2, 1952 MAGNETIC LOOK FOR MINERS SAFETY LAMPS Grant Wheat and Arthur G. Davis, Marlboro, Mass, assignors to Koehler Manufacturing Company, Marlboro, Mass., a corporation of Massachusetts Application May 16, 1951, Serial No. 226,634

This invention relates to miners lamps of the type commonly referred to as "safety flame lamps which can be ignited while in a substantially closed state through a spark igniter mechanism designed to be operated by hand from a point outside of the enclosing structure of the lamp.

In general, such a lamp includes a fount for holding a supply of naptha, or other liquidfuel; a burner of the wick type; a. substantially unbreakable glass chimney encircling the wick; a woven Wire mesh gauze and bonnet above the chimney; a dome top above the bonnet; and mean for holding these parts together in their assembled relationship. With these elements it is customaryto combine a spark igniter which has an externally located operating knob or handle, and conventional structures of this nature are objectionable owing to their being relatively cum bersome; occupying considerable space in the fount, and being difficult to remove.

The present invention deals with the problems indicated and aims to improve safety lamp structures and their spark igniter mechanism with a view to facilitating. the servicing and maintenance of such devices. It is also an object of the invention to devise a structure which will be stronger, simpler, and more economical to manuiacture, as well as one that will be more convenient to use. It is still further an object of the invention to provide an apparatus having outstanding safety features.

A further object of this invention is to provide a magnetic locking means for the safety lamp, the locking means being located internally of the locking rings and having means in the fount cooperating with the magnetic lockingmeans for releasably securing the locking rings on the fount. J

These and other objects and novel features will be more fully understood. and appreciated from the following description of a preferredembodiment of the invention selected. for purposes of illustration and shown in the accompanying drawings, in which Fig. 1 is a vertical, sectional view, partly in elevation, illustrating the improved safetylamp construction of the invention;

Fig. 2 is a perspective view of thesafety lamp fount showing the spark igniter of, the invention removed therefrom; V

Fig. 3 is a view somewhat similar, to Fig.2 but illustrating the igniter partly installed in the fount; I

i Fig. 4 is a pla n view armament with. the

1 Claim. (01. 240-19) 2 igniter fully installed and shown in proper operating relationship with respect to the burner element of the lamp;

Fig. 5 is anotherview of the ignitermechanism shown in Figs. 1 to'4, inclusive; 7 v Fig. 6 is a fragmentary plan view of the upper side of the fount, further illustrating the aperture through which the igniter member is inserted in installing the latter member in its proper operating position;

Fig. 7 is a cross-sectional view taken centrally through the igniter apparatus, showing the relationshi of the igniter elements to ;one another; Fig. 8 is an enlarged detailed elevational view of the head of the igniterj Fig. 9 is an end elevational view of thestructure shown in Fig. 8; a

Fig. 10 is a view similar to Fig; 9 but illustrating a different operating position of thelelements appearing thereiny. a

Fig. 11 isa detailed view. of a camengaging memberfxz Fig. 12 is a detailed 'elevational view of the cam engaging element shown in. Fig. 11 mounted on its supporting shaft; and. 1

Fig. 13 is a detailed planview showing parts of the magnetic locking mechanism-also indicated inFig. 1. J Referring first to Fig. l, the Iampstructure there shown comprises a fount 2 provided with an integral annular neck 3 rising from its top, and this neck is slotted at several points,'some of which are shown at 4, for the passage ofair therethrough. Resting on'the fount inside the neck is an air admission ring 5 and'it is shaped to provide a seat for the bottom of the-- glass chimney 6, a gasketbeing-interposed between said seat and the lowerend of the chimney. I On top of this chimney isanother-ring ilbarrying a gasket 9. The flanged lower'end of the inner gauze cone I 0 seats 'on 'ring8 While the flanged cupped lower end of outer gauze cone l2 seats on the flange of innergauzecone I0. .I Surrounding these cones is'a bonnet I3resting at its lower end on a middle ring ldpand supported on the top ofthis bonnet is a ringl 5, 'both of the rings I4 and I5 having numerous holes for the passage of air therethrough. Atthe extreme top of the lamp structureisa dome top I 6 covering the upper end of the bonnet, and the usual carrying hook His attached to.it. f ,1

In order to secure these main'portions of this lamp structure rigidly together, several retaining rods [8, in this instancefive, are; arrangedzto connect the top andbottomelements-of this assembly portion of one of the rods 18, is interposed between the lock ring and the middle ring it wherethey space these two elements apart. The middle and top rings are spaced apart by the bonnet 13.

Above the bonnet several short tubes 2; encircle the upper portions of the respective rods l-8- and space the dome top Hi from the top ring iii'by a distance ample to provide ventilation.

Nuts 23 threaded on the upper ends of the rods This construction simplifies the servicingof the lamp;v makesitmore: reliable, and less likely to get out oforder. It'also .providesa very rigid top unit convenient; to. handle. .in'unscrewing the fount-from it, asi's necessarywith the frequent refilling and other maintenance operations' The fount is filled through an openingin its top normally closed by a screw-threadedmezm berlofithe conventional type. Servicing of the lampincludes, inaddition to refilling, the cleaning of the chimney 6, the bonnetandgauzes, and theinspection and cleaning of :the wick and the ignite-r. In reassembling the parts after cleaning, the bolts I8v are checkedto be sure that they are tight, and the factthat thereis only a limited number of these boltsas,: for example five, as compared'to a much larger number, as in prior artconstructions, plus :the further fact that an inspection of them consists in trying themwith a ascrew-driver at the bottom of the ringZO in order to-see if they are tight, reduces thework involved and eliminates some of the opportunities for error ofsinspection.

It .should be noted. that the heads of the bolts l8;are.concealed within thering 20 when the assembly. is in its normally operative position, which protects the heads of :the bolts against tampering. To this same end the enclosingtubes 2| for the rods. (8,; as well as-the short tubes 22, areconstructed with an inner diameter slightly exceeding the diameter of the enclosed rod members so that'the. tubularmembers'if turned, for

example by means .of a wrench, or-other-tool, will be revolved freelvaround therods without engaging these members, andtherefore without producing .anylikelihood of indirectly threading the .rods out of. engagement with the nuts, either at thebottom or:top..of the lamp structure It will readily. be appreciated that if these tube members were not loosely contained about their respective rod portions it would be possible for an operator, while in the mine, to turn the tubes and thus unthread the rods and release the fount from the remaining portions of the lamp structure and increase the risk of an explosion. v With the shrouded bbltand tubearrangement 4 above described, however, and with the fount assembled, it is a simple matter to tighten the bolts after replacing the parts in the course of routine cleaning operations. As noted, each of the nuts 23 at the upper ends of the bolts is seated in a depressionpr socket formed in the dome top [6 which functions in the nature of a shroud to prevent the nut from being rotated. ;In using safety lamps of the character described it is, in many cases, essential to provide a means for locking the lamp parts in fixed relation to one another so that these parts cannot be disengaged while the lamp is in use in the mine. To deal with this problem we have combined with the; concealed locking rod structure a magnetic locking means which comes into operationwhen the lamp parts are brought into a fully assembled relationship. This provides a unique combination of lockingmeans for achieving the desired result and yet afiording a convenient control. of the lock.

As shown in Figs. land 13, we. provide. in: the member 20 .arecess 20a inwhi'ch is locateda look-- ing. member 2flb'suppo'rted-for rotation. abouta pivot member 200. Aslot: 20d extends. through the inner wall. of the member 2B. and: communiicates with the opening 20a to provide a passageway through which alocking tip 211s of. the locking member 29b isznormally.forced'by-means of.'a spring 20];

The arrangementof thelocking membenissuch that it is sensitive to 'theactio'rrof amagnet: of the horse-shoetype, for example, the pole faces of which are placed on. magne'tiz-able. studs: at the upper side of the. memberlO. The. magnet acts through thestudsto pivotithe lockingmember 20b in a mannerwell-known in the: artand in a direction counterclockwise, .as viewed in Fi (3, so that the locking-tip: Zoe-is pivoted against the spring 20; and into the passageway ZQd'sufil ciently to allow the. member 20. to beefreely turned about the ,threadedGneck of the fountand thus permit removalof the. latter member from the lamp.

In using-the combination lockingrod-and magnetic locking device described; it .will be.- under;- stood that the fountand locking ring, when in fully threaded position, arelocked in place. by thetip 20c. In .thiscondition the lamp iscarried into the mine by-;-the.- miner who is using it. At the-end of the day, when thev miner returnsto: the point of inspection andzservicingofrthe lamps, he is required :to deliverthe lamp tothe lamp man inthe lamp house.- Thelampman is .underrigid inspection and is' the. only one-allowedto havea magnet. He usesthe magnetat thistime torelieve thelocking member 29a, thus. permitting the removal of thefou'nt for servicing operations.

In one preferred embodiment of the invention We combine with a. safety-lamp structure, as above described, a .'novel spark ignite'r-mechanism in the form oi 'a' compact igniter unit-which is easily installed: andzremove'd from the fount of a safety lamp and designed tobe-furnished as a replaceable item. This unit is of-the spark type including a friction wheel or disk 50,-more clearly shown inFigs. 4, '7 and 8, and provided-withfi-le cut edges working against a piece of flint or pyro metal 52 resiliently heldin atubular body 54 by means of a coiled spring '55 and a set screw "56. In the construction provided by 'the invention, the parts just mentioned are mounted on a cylindricalbushing 58 rigidly'fastened by a screw 60 (Fig. 7) in a cylindrical holder 25. The lat .ter member-has aflat bottom surface adapted to rest on the top plate 62 of the fount 2. Located through the plate 62 is a circular aperture 64 (Fig. 6) which is formed with a straight overhanging edge 65. V

The friction wheel 50 is fixed on a shaft 65 which is eccentrically mounted for rotation in the bushing 58. One end of a spring 68 is anchored to the bushing 58 and the other end extends around, and is secured to, the shaft 66. At its inner or lower extremity the shaft 66 has mounted on it in fixed relation an eccentric cam 10 which extends radially outward and is resiliently held against a stop 12 solidly located on the bushing 58, as is better shown in Figs. 9 and 10. The cam 10 and stop 12 are arranged in spaced relation to the inner bottom surface of the holder 25, as will be noted in Fig. 7.

Supported in the fount 2 is a receiver 21 of generally tubular form which extends through the body of the fount and is sealed at opposite ends to the top and bottom plates of the latter member. It is desirable to have the top of the igniter occupy a position no higher than the top of the burner 24 when the lamp is in operation and, consequently, it is necessary in lighting the lamp to raise the friction wheel and flint assembly into such position that the spark produced by the operation of the latter will be on approximately a level with the top of the wick W, shown in Fig. 4 of the drawings.

To satisfy these conditions we have first provided a port I4 (Fig. 1) which is formed in the side of the igniter holder 25 and through which a spark from the igniter may be directed across the top of the wick when the ignter is in a raised position. To raise the igniter into proper operating relationship with the wick W, the holder 25 is constructed at its inner end with a reduced cylindrical stem which is slidably disposed through the fount plate 62 and which extends into the upper hollow end of the receiver 21. This reduced cylindrical stem comprises two bosses 28 and 29, more clearly shown in Figs. 2, 3, and 7. The bosses 28 and 29 are spaced apart by an intermediate cylindrical part 30 of lesser diameter.

Cooperating with the igniter holder and its reduced cylindrical stem is a shaft 3| extending from one end of the receiver 21 through the reduced stem into the lower end of the holder 25, as noted in Fig. 7. The outer extremity of shaft 3| is threaded to receive an operating knob 33. A coiled spring 34 encrcles the shaft 31, when the parts are in their operative positions, as shown in Fig. 7, and the spring abuts at its upper end against a shoulder in the receiver 21,

and at its lower end against an adjacent portion of the knob 33. Consequently, this spring tends to hold the igniter in a lowered position with respect to the receiver 21. At its opposite or upper end the shaft 3| solidly supports a thin disk 'IB which is received within the member 25 in a position to bear against the bottom inner surface of the latter member. The disk is provided with a cam engaging projection 18, more clearly shown inv Figs. 11 and 12. The projection 18 is arranged on the outer peripheral edge of the disk in a position chosen such that it may move into engagement with the eccentric cam in one location of the latter member, such as that shown in Fig. 9, for example. When the shaft 31 and disk are rotated by the knob 33 in a clockwise direction, the cam 18, together with the friction wheel shaft 66, will be rotated against the holding effect of the spring 68. As rotation continues,

the projection [8 slides outwardlyalone the cam 10, and at some predetermined point; such as that shown in Fig. 10, will release the cam 10 allowing it to spring back to its starting position against the stop member 12.;

In operating the igniter, theknob 33 is first pushed upwardly carrying the friction wheel and flint up to the level of the wick W where they are firmly held. The knob 33 is then, at thes'ame time, turned in a clockwise direction to rotate the friction wheel 'through alimited arc of rotation, after which its connection with the shaft3l is released, as above described, and the spring 68 operating through the energy stored in it by the rotation, produces a quick rotative movement of thedisk in the opposite direction. This movement operates by contact of the disk with the flange 52 to produce the spark which lights the wick W. After the spark has occurred the knob is released and the spring 34 returns the knob and the igniter to their origi nal starting positions. 7

During the upward movement ofcthe knob 33 and the igniter, boss 28 slides through the hole 64 in the top plate of the fount. This boss 28 is of a shape and dimension to fit snugly within the hole 64 with a small operating clearance, and in order toaccomplish this, boss 28 is formed with a fiat 28a, better shown in Fig. 5. Similarly, the boss 29 is of the same peripheral shape correct position for directing a spark across the v wick when the upper surface of the boss 29 is forced against the under surface of the plate 62 of the fount. The boss, therefore, serves as a stop to limit upward movement of the igniter during the lighting operation. It may here be observed that the igniter support 25 and the bosses 28 and 29 are all coaxial with the shaft 3|, and the curved surfaces of the bosses are 7 concentric with those of the members 25 and 30.

Occasionally it is necessary to remove the igniter from the fount, and this operation can be performed by turning the knob 33 counterclockwise andthereby unscrewing it from the shaft 3|, after which the igniter body can be lifted until the boss 29 strikes the under side of the overhanging edge 65 of the top plate of the fount. Then by giving the igniter a quarter turn in a counter-clockwise direction, the lower boss 29 is brought into the proper position to pass through the-hole 35 with the flat 29a lying in register with the edge 65 of the plate. The entire igniter body can then be lifted out, as suggested in Fig. 2, and replaced with a new unit, or suitable repairs made. as are necessary.

When installing the igniter the lower boss 29 is brought into the position suggested in Fig. 2 with the fiat 29a lying in register with the edge 65 of the opening 64. In this position it will be observed that the tubular member 54 projects which the upper fiat 28a of boss 28 registers with 9 the edge 65andiallowsthe boss 28 to be dropped 7 down until the member -25 seats on the top plate of the fount. In-the' latter position described it will be observed that the tubular member 1 has been swung around into a positionsuch as is illustrated in Fig. 4, inwhich it no longer ='pro jects above the neck of the founti An important feature o'fthe' invention is the cooperative locking efiect derived front the location of the tubularmember fi i iwi th respect to the fiat 29a. As noted above,- thefiat ZSwis= so located on the boss ZS -thatOr-derfor the flat to register with the overhanging edge 65, the tube 54 must project outwardly over the fountneck. By reason ofa this fact it' will: be: seen that a fully assembled position of-tlielamp chimney it will be impossible for the: tubular member :to move into a position where the" igxiiter can 'be completely removed fronrtlr-i'e founti- Suclta lock is" importantbecause it prevents the ig ni-ter from falling out of the founliiiZ-tlie-lampshould be turned upside down at atime when the moves has been removed. r

It will also be seen thatit isirhperativeitoniainta in the port l lproper register with the wick W, and this is provided fonb ythe fiat 28a at the boss 28 being-locked against; the' 'edge 65 when the receiver is in a? fullyseated position on the topplate of the. iount; shown in: Figs 4. Therefore, when in. the DOSi iTiGIL shown-in 4 andI'in apartly raised state, suchz asiisefrected by means ofithetlmoli 33; regi'ster'of: theiport with the wiclii's always maintained.:.

Thus itiwiilbewobseiiveditliatin ordertoi remove the ignitei: from the: fount,..it is: neeessary: not only'to removetlre knobrbut also to pro'ducerslidable. and; rotative movements of: predetermined degree. of the igniter: body; in order. to effectits release, It. should be! observed that the; nation theboss 23;.as note'diabove,.isiin a plane; at right angles to the. axis. of the tube .Mand that-the flat on the lower boss ZQiis also parallel to'ttliat axis. and. in aplane perpendicular to the-'flrst noted plane. The edge Gain the hole 641 is also at right angles to the: axis; entire-tube whenlthe igniteriis in its operative position. Consequently, if the' operating knob should be removed: with therest of the lamp s'till assembled-arid lighted, it would be impossible to raise the: igniteniar enough to freei it from. the hole: Also; the rotative movement of theig-nit'er. essentialito-its removal. would. be prevented". by! ther-igniterr tube striking the inner Weillof the: glassi chi'mney" S. This will be olearlyseenirom:aninspeotion of Figs. Zan'd 4 The foregoing safeguards are? important: be cause if the igniter could b'eipushediuprout of the remit merely by removing.tl1e.-l :nob;.a hole would be provided through which surroundingi air and gases could flow into thewick chambei' inside the chimney t and-ii -these g'ases we'reacombustible, explosionmight-be produced; Toifurther aid in understanding this danger, it slioulil be-appreelated-that through the air admissionring tliere is always air (andxgasif present) ilowi'ngintothe wick chamber, a movement which-iscaiised by the effect oftherlame creatingia snot-ions Should a mixture or air and gasreach a point at which it isexplosive, an-ig nition may take place inside the chinmey andinnergauze;- This isliairmless as long as tliereare no openings large'enough for a flame togo' througliand reach the surrounding outside air; Actually-this internal type-of explosion often takesmlace. Itsworseeffect is toiextin'guishtheiflanie W hfeh' thls'ignitiondnside the:lamp takesz'placetthe -suction is changed to a pressure and the eaiigercomes-rr'ont the flame leaking out of the lamp, igniting gas on the outside.

A further provision made for the purposeof preventing the entrance of combustible gases into the lamp consists-in providing the restriction 36 hi the=bore of the tubular receive-r 21. That is, thisbore-isfsorestrieted immediately above the spring d i that it closely encircles the shaft 3i and revents-anyappreciable leakage of gases around this opera-tingelement-for the igniter and into'the wickcliarnberl will be seen that the use-or two spacedapartbosses witli iiats at i i'ghtang-ls to one another, in order to looli ig niterin thedesired positions the iount is made pds'sibleby combining W these b e's' an intervening reduced oylii ldria'il' pbftidn 30 Wliio'if rovides for" necessary rotativ movement; This applicationis a continuation-in part of application Sel No.

' 665GB; filed December 20, 1948.

Wliile'we have herein shown and described a preferred embodiment of our invention, itis com templated -tliatthe igniter mechanism may be 'iltilizedwithvarious other types of lamps and tl i'e invention-may beembodied in other forms without departing from the spirit or scope thereof We claim:

In a' miners safetyl'amp, a fount-liaving an externally threaded flange set inwardlyfrom its upper marginal edge and providing an upwardly facing annular shoulder, an aperture formed in said threaded flange, a lockring in threaded engagement'with said flange and having bolt sockets in its under face and bolt openings extending vertically from said sockets, an elongated arouate recess formed in the bottom face of the lock ring between certain of said bolt openings, said recess being spaced inwardly from the outer face of the lock ring, an opening extending through theinner wall or the recess, a locking member including divergingarms and formed of material subject to magnetic attraction arranged insaid recess, said locking member being pivotally mounted medially in said recess and one arm of said locking member terminating in an inwardly extending hook, a spring between one side ofthe other arm of the locking member and the adjacent wall of the recess, said spring normally lliggil'lg said hook through theaperture in the side wall of the recess and into the aperture of the flange, magnetizable studs extending downwardly through the upper wall of the locking ring at opposite sides of each of said arms for association with a U-magnet, said studs being normally spaced from said arms and extending intothe path of movement of the same, whereby said locking member may be-swung on its pivot against said magnetizable studs to move said hook from locked to'unlocked position, said lock ring being adapted'to have its under face seated upon the shoulder of said fount to close said socketopenings and said recess, transverse air ports'formed in the bottom of said flange, an air induction ring seating on said fount inwardly of the flange, said ring being formed'with lateral annular shoulders, a chimney supported on the shoulders, at gauze cone supported on the top of the chimney having an outwardly flanged bottom, aperforated ring supported uponsaid cone shoulder, the perforations in said ring being vertically aligned with the boltopenings in said lock ring,

a hood supported onsaid ring outwardly of said perforations, -atop ring on said hood, and a dome formed with perforations aligned with the perforations in said first ring and said lock ring, said dome being depressed adjacent its perforations to form nut shrouds, bolts having their heads seated in the bolt sockets in said lock ring and extending through said rings and dome, said bolts having associated nuts seated in the shrouds in said dome and adjusted by operation of their heads in said lock ring, and tubular supports of greater diameter than said bolts enclosing exposed portions of the latter, said tubular supports being supported at their lower ends upon said lock ring and having their upper ends in supporting engagement with said perforated ring.

GRANT WHEAT. ARTHUR G. DAVIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 509,418 Wolf Nov. 28, 1893 749,123 Wiedenfeld Jan. 5, 1904 1,218, 85 Jones Mar. 6, 1917 10 1,979,837 Lueck et a1. Nov. 6, 1934 FOREIGN PATENTS Number Country Date 21,840 Great Britain of 1896 25,933 Great Britain 1 of 1902 2,327 1 Austria Oct. 10, 1900 

